That's a toughie... .NET assemblies are not really designed to be "edited", for security and integrity reasons. I could see possibly disassembling and recompiling the assembly. You could, for instance, use Microsoft's ILDasm tool to extract the IL and resources, try WinZip to decompress the resource files, edit them, and recompile the whole thing using ilasm.

Because the package code set the "compression" flag, you would probably have to zip the resources again before compiling, but I'm unsure whether Packager's "zlib.dll" can decompress WinZipped files. If you're really, really stuck and can't repackage, then this is the only way I can think of.

Your best option would be to modify the procedure in the database and repackage the whole database.